Purpose: To examine efficacy of 12 months Football Fitness offered twice per week on bone mineral density (BMD), bone turnover markers (BTM), postural balance, muscle strength and body composition in women treated for early-stage breast cancer (BC).

Methods: Women treated for early-stage BC were randomised to Football Fitness (FFG, n=46) or control (CON, n=22) in a 2:1 ratio for 12 months, with assessments performed at baseline, 6 months and 12 months. Outcomes were total body-, lumbar spine- and proximal femur BMD, total body lean and fat mass, leg muscle strength, postural balance, and plasma amino-terminal propeptide of type 1 procollagen (P1NP), osteocalcin and C-terminal telopeptide of type 1 collagen (CTX). Intention-to-treat (ITT) analyses and per-protocol analyses (≥50% attendance in FFG) were performed using linear mixed models.

Results: Participants in FFG completing the 12-month intervention (n=33) attended 0.8 (SD=0.4) sessions per week. Intention to treat analysis of mean changes over 12 months showed significant differences in L1-L4 BMD (0.029 g/cm2 , 95%CI: 0.001 to 0.057), leg press strength (7.2 kg, 95%CI: 0.1 to 14.3) and postural balance (-4.3 n need of support, 95%CI: -8.0 to -0.7) favouring FFG compared to CON. In the per-protocol analyses, L1-L4 and trochanter major BMD were improved (p=0.012 and 0.030, respectively) in FFG compared to CON. No differences were observed between groups in BTMs in the ITT or per protocol analyses.

Conclusion: One year of Football Fitness training may improve L1-L4 BMD, leg muscle strength and postural balance in women treated for early-stage breast cancer.